Meta projector and electronic apparatus including the same

ABSTRACT

A meta projector includes an edge emitting device configured to emit light through a side surface thereof, a meta-structure layer spaced apart from the upper surface of the edge emitting device that includes a plurality of nanostructures having a sub-wavelength shape dimension smaller than a wavelength of the light emitted from the edge emitting device, and a path changing member configured to change a path of the light emitted from the edge emitting device so as to direct the path toward the meta-structure layer. The meta projector may thus be configured to emit a light pattern of structured light, based on directing the light emitted from the edge emitting device through the meta-structure layer, while having a relatively compact device size.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit, under 35 U.S.C. § 119, of KoreanPatent Application No. 10-2017-0097134, filed on Jul. 31, 2017, in theKorean Intellectual Property Office, the disclosure of which isincorporated herein in its entirety by reference.

BACKGROUND 1. Field

The present disclosure relates to a meta projector and an electronicapparatus including the meta projector.

2. Description of the Related Art

Recently, demand has gradually increased for small laser projectors forcombination with various electronic apparatuses.

For example, ultra-small projectors may be used for augmented reality(AR), virtual reality (VR), and mixed reality (MR) implemented by mobileand wearable devices, and laser projectors may be used to formstructured light in depth sensors used to accurately recognizethree-dimensional shapes of objects such as humans or other things.

In general, lighting components for laser projection are fabricatedusing micro-optic technology, and a plurality of optical components arenecessary to achieve desired performance. The volume occupied by suchoptical components is a factor affecting design precision andfabrication conditions.

SUMMARY

Provided are meta projectors having ultra-small size and configured tooutput light with desired performance (e.g., structured light having aparticular pattern).

Provided are electronic apparatuses including one or more metaprojectors.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

According to some example embodiments, a meta projector may include asubstrate, an edge emitting device on the substrate, a meta-structurelayer spaced apart from the upper surface of the edge emitting device,and a path changing member. The edge emitting device may include anupper surface extending parallel to the substrate and a side surfaceinclined relative to the upper surface, the edge emitting deviceconfigured to emit light through the side surface. The meta-structurelayer may be spaced apart from the upper surface of the edge emittingdevice. The meta-structure layer may include a plurality ofnanostructures having a sub-wavelength shape dimension, thesub-wavelength shape dimension smaller than a wavelength of the lightemitted from the edge emitting device. The path changing member may beconfigured to change a path of the light emitted from the edge emittingdevice to direct the path toward the meta-structure layer.

The meta projector may further include a housing fixing the substrate,the meta-structure layer, and the path changing member, such that themeta projector is an integrated module.

The substrate may include a cathode and an anode respectively connectedto two electrodes of the edge emitting device; and an insulating layerelectrically isolating the cathode and the anode from each other.

The plurality of nanostructures may include a material having arefractive index higher than a refractive index of a separate materialadjacent to the plurality of nanostructures.

The plurality of nanostructures may include a conductive material.

The plurality of nanostructures may be associated with a shapedistribution that is a regular distribution or a random distribution,such that the plurality of nanostructures are configured to formstructured light having a particular pattern based on receiving thelight emitted from the edge emitting device.

The shape distribution of the plurality of nanostructures may beassociated with deflecting and outputting the structured light in aparticular direction.

A shape distribution of the plurality of nanostructures may beassociated with different transmission phase distributions based onpolarization of incident light.

Shapes of cross-sections of the plurality of nanostructures parallel tothe upper surface of the edge emitting device may have asymmetry.

The plurality of nanostructures may be associated with an arrangementpitch which is equal to or less than one-half of the wavelength of thelight emitted from the edge emitting device.

The meta-structure layer may further include a support layer supportingthe plurality of nanostructures, and the plurality of nanostructures mayinclude separate pluralities of nanostructures on opposite, respectivesides of the support layer.

One plurality of nanostructures on one side of the opposite, respectivesides of the support layer where the light emitted from the edgeemitting device first arrives may be associated with a shapedistribution associated with a transmission phase distribution thatincreases a divergence angle of incident light.

The path changing member may include a reflective surface configured tobend the path of the light emitted from the edge emitting device by aparticular angle.

The reflective surface may include a curved surface configured to adjusta divergence angle of incident light.

The reflective surface may include a meta-surface, the meta-surfaceincluding a plurality of nanostructures, the plurality of nanostructuresassociated with a sub-wavelength shape dimension smaller than thewavelength of the light emitted from the edge emitting device.

A shape distribution of the plurality of nanostructures of themeta-surface may be associated with adjusting a divergence angle ofincident light.

A shape distribution of the plurality of nanostructures of themeta-structure layer may be associated with forming structured lightproviding a keyboard image in which a set of character keys is arrangedor an image including at least one icon.

A user interface device may include the meta projector and an imagingdevice configured to photograph an image formed by the meta projector.

An electronic apparatus may include the user interface device, a memoryconfigured to store at least one program of instructions, and aprocessor configured to extract a user input signal from an imagecaptured by the imaging device and execute the program of instructionsaccording to the user input signal.

A depth recognition apparatus may include the meta projector configuredto emit structured light toward an object, a sensor configured toreceive the structured light reflected from the object, and a calculatorconfigured to compare a pattern of the structured light emitted towardthe object and a pattern of the structured light reflected from theobject, and calculate a depth position of the object.

According to some example embodiments, a meta projector may include asubstrate, an edge emitting device on the substrate, and a path changingmember configured to change a path of the light emitted from the edgeemitting device. The edge emitting device may include an upper surfaceextending parallel to the substrate and a side surface inclined relativeto the upper surface, the edge emitting device configured to emit lightthrough the side surface. The path changing member may include areflective surface configured to bend the path of the light emitted fromthe edge emitting device by a particular angle, the reflective surfaceincluding a meta-surface, the meta-surface including a plurality ofnanostructures, the plurality of nanostructures associated with asub-wavelength shape dimension smaller than a wavelength of the lightemitted from the edge emitting device.

The reflective surface may include a curved surface configured to adjusta divergence angle of incident light.

A shape distribution of the plurality of nanostructures of themeta-surface may be associated with adjusting a divergence angle ofincident light.

A shape distribution of the plurality of nanostructures of themeta-surface may be associated with forming structured light providing akeyboard image in which a set of character keys is arranged or an imageincluding at least one icon.

The substrate may include a cathode and an anode respectively connectedto two electrodes of the edge emitting device; and an insulating layerelectrically isolating the cathode and the anode from each other.

The plurality of nanostructures may include a material having arefractive index higher than a refractive index of a separate materialadjacent to the plurality of nanostructures.

The plurality of nanostructures may include a conductive material.

According to some example embodiments, a meta projector may include asubstrate, an edge emitting device on the substrate, and a plurality ofnanostructures. The edge emitting device may include an upper surfaceextending parallel to the substrate and a side surface inclined relativeto the upper surface, the edge emitting device configured to emit lightthrough the side surface. The plurality of nanostructures may beconfigured to receive the light emitted from the edge emitting deviceand generate a structured light pattern based on receiving the lightemitted from the edge emitting device, the plurality of nanostructureshaving a sub-wavelength shape dimension, the sub-wavelength shapedimension smaller than a wavelength of the light emitted from the edgeemitting device.

The plurality of nanostructures may be included in a meta-structurelayer spaced apart from the upper surface of the edge emitting device.The meta projector may further include a path changing member configuredto change a path of the light emitted from the edge emitting device todirect the path toward the meta-structure layer.

The plurality of nanostructures may be included in a path changingmember of the meta projector, the path changing member configured tochange a path of the light emitted from the edge emitting device. Thepath changing member may include a reflective surface configured to bendthe path of the light emitted from the edge emitting device by aparticular angle. The reflective surface may include a meta-surface, themeta-surface including the plurality of nanostructures.

The reflective surface may include a curved surface configured to adjusta divergence angle of incident light.

A shape distribution of the plurality of nanostructures of themeta-surface may be associated with adjusting a divergence angle ofincident light.

A shape distribution of the plurality of nanostructures of themeta-surface may be associated with forming structured light providing akeyboard image in which a set of character keys is arranged or an imageincluding at least one icon.

The substrate may include a cathode and an anode respectively connectedto two electrodes of the edge emitting device; and an insulating layerelectrically isolating the cathode and the anode from each other.

The plurality of nanostructures may include a material having arefractive index higher than a refractive index of a separate materialadjacent to the plurality of nanostructures.

The plurality of nanostructures may include a conductive material.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings in which:

FIG. 1 is a cross-sectional view illustrating a schematic configurationof a meta projector according to some example embodiments;

FIG. 2 is a cross-sectional view illustrating an example configurationof an edge emitting device included in the meta projector of FIG. 1;

FIG. 3 is a perspective view illustrating an example configuration of ameta-structure layer that may be employed in the meta projector of FIG.1;

FIG. 4 is a perspective view illustrating an example configuration ofanother meta-structure layer that may be employed in the meta projectorof FIG. 1;

FIGS. 5 to 8 are perspective views illustrating example shapes ofnanostructures applicable to the meta-structure layer of the metaprojector of FIG. 1;

FIG. 9 is a perspective view illustrating an example configuration ofanother meta-structure layer applicable to the meta projector of FIG. 1;

FIG. 10 is a cross-sectional view illustrating a schematic configurationof a meta projector according to some example embodiments;

FIG. 11 is a cross-sectional view illustrating a schematic configurationof a meta projector according to some example embodiments;

FIG. 12 is a cross-sectional view illustrating an example configurationof a meta-surface of the meta projector of FIG. 11;

FIG. 13 is a cross-sectional view illustrating a schematic configurationof a meta projector according to some example embodiments;

FIG. 14 is a block diagram schematically illustrating a user interfacedevice and an electronic apparatus including the user interface device,according to some example embodiments.

FIG. 15 is a block diagram illustrating a schematic configuration of adepth recognition apparatus according to some example embodiments.

DETAILED DESCRIPTION

Reference will now be made in detail to example embodiments, at leastsome of which are illustrated in the accompanying drawings, wherein likereference numerals refer to like elements throughout. In this regard,some example embodiments may have different forms and should not beconstrued as being limited to the descriptions set forth herein.Accordingly, the embodiments are merely described below, by referring tothe figures, to explain aspects. As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items. Expressions such as “at least one of,” when preceding alist of elements, modify the entire list of elements and do not modifythe individual elements of the list.

Hereinafter, embodiments of the present disclosure will be describedwith reference to the accompanying drawings. In the drawings, likereference numbers refer to like elements, and the sizes of elements maybe exaggerated for clarity of illustration. The embodiments describedherein are for illustrative purposes only, and various modifications maybe made therefrom.

In the following description, when an element is referred to as being“above” or “on” another element, it may be directly on the other elementwhile making contact with the other element or may be above the otherelement without making contact with the other element. Furthermore, whenan element is referred to as being “on” another element, it will beunderstood that the element may be above or below the other element.

When the terms “about” or “substantially” are used in this specificationin connection with a numerical value, it is intended that the associatednumerical value include a tolerance of ±10% around the stated numericalvalue. When ranges are specified, the range includes all valuestherebetween such as increments of 0.1%.

As used herein, the singular forms “a,” “an”, and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising” used herein specify the presence of stated featuresor elements, but do not preclude the presence or addition of one or moreother features or elements.

In the present disclosure, terms such as unit or module are used todenote a unit having at least one function or operation and implementedwith hardware, software, or a combination of hardware and software.Terms such as “unit” or “module” may further be used to denote aninstance of hardware that is configured to perform the at least onefunction or operation.

FIG. 1 is a cross-sectional view illustrating a schematic configurationof a meta projector 100 according to some example embodiments. FIG. 2 isa cross-sectional view illustrating an example configuration of an edgeemitting device 120 included in the meta projector 100 of FIG. 1. FIG. 3is a perspective view illustrating an example configuration of ameta-structure layer MS that may be employed (“included”) in the metaprojector 100 of FIG. 1.

The meta projector 100 includes: the edge emitting device 120; themeta-structure layer MS spaced apart from the edge emitting device 120and configured to convert light 132 emitted from the edge emittingdevice 120 into structured light SL having a particular (or,alternatively, predetermined) pattern and output the structured lightSL; and a path changing member 140 configured to change a path of thelight 132 emitted from the edge emitting device 120 to direct the pathtoward the meta-structure layer MS.

When light 132 generated by the edge emitting device 120 is incident onthe meta-structure layer MS, the meta-structure layer MS forms adistribution of light rays propagating in space based on the incidentlight 132. Such light rays form a beam spot in an angular space and arevariously distributed according to conditions applied to themeta-structure layer MS. These light lays are called structured lightSL.

The structured light SL generated by the meta-structure layer MS mayhave a pattern mathematically coded to uniquely designate angularposition coordinates using bright and dark points. Such a pattern may bechanged in shape by a three-dimensional object, and this change may beimaged using an imaging device such as a camera so as to extract depthinformation about the three-dimensional object by comparing patterns andtracing the degree of variation in pattern shape according tocoordinates.

The edge emitting device 120 may be placed (“located”) on a substrate110 and may include an upper surface 120 a extending in parallel withthe substrate 110 and a side surface 120 b inclined relative to theupper surface 120 a (e.g., side surface 120 b may extend orthogonallyrelative to the upper surface 120 a, as shown in FIG. 1). The sidesurface 120 b is a light exit surface.

As shown in FIG. 1, the meta-structure MS is spaced apart from the uppersurface 120 a of the edge emitting device 120 according to spacingdistance 170. As shown in FIG. 1, the meta structure MS may extend inparallel or substantially in parallel (e.g., parallel withinmanufacturing tolerances and/or material tolerances) to the uppersurface 120 a of the edge emitting device 120. Since the meta-structurelayer MS is placed above the edge emitting device 120, and light 132exits the edge emitting device 120 through the side surface 120 b, apath changing member 140 is further provided between the edge emittingdevice 120 and the meta-structure layer MS, where the path changingmember 140 is configured to change the path of light 132 exiting theedge emitting device 120 such that the path may be directed toward themeta-structure layer MS, as shown in FIG. 1. The path changing member140 may include a reflective surface 140 a which is configured to bendthe propagation path of light 132 exiting the edge emitting device 120by a particular (or, alternatively, predetermined) angle. For example,in the example embodiments shown in FIG. 1, the reflective surface 140 amay be configured to bend the propagation path of light 132 byapproximately 120 degrees. The reflective surface 140 a may bemirror-coated. The inclination angle of the reflective surface 140 a isassociated with the position of the meta-structure layer MS relative tothe side surface 120 b which is a light exit surface of the edgeemitting device 120, so that the reflective surface 140 a is configuredto bend the optical axis of light by a particular (or, alternatively,predetermined) angle. For example, the optical axis of light may be bentin a vertical direction or may be bent such that light may propagate ina direction inclined leftward by about 30°.

An example configuration of the edge emitting device 120 will now bedescribed with reference to FIG. 2.

The edge emitting device 120 includes a lower clad layer 121 and anupper clad layer 125 spaced apart from each other. A gain region 123 isprovided between the lower clad layer 121 and the upper clad layer 125.A first mirror region 122 and a second mirror region 124 are placed(“located”) on both sides (“opposite sides”) of the gain region 123. Thefirst mirror region 122, the gain region 123, and the second mirrorregion 124 form (“at least partially comprise”) a laser cavity LC.

The gain region 123 may include a material configured to generate lightin a particular (or, alternatively, predetermined) wavelength band(“wavelength spectrum of light”) when electrons and holes are injectedthrough a first electrode 127 and a second electrode 128. The gainregion 123 may have a group III-V compound semiconductor, or a quantumwell or dot structure based on a group III-V compound semiconductor.

The lower clad layer 121 and the upper clad layer 125 may include asemiconductor material having a larger band gap than the gain region123. For example, the lower clad layer 121 and the upper clad layer 125may include GaAs, GaP, AlGaAs, InGaP, or InGaAlP.

The first electrode 127 may be provided on a lower surface of the lowerclad layer 121, and the second electrode 128 may be provided on an uppersurface of the upper clad layer 125, so as to inject current into thegain region 123. A contact layer (not shown) may be further providedbetween the lower clad layer 121 and the first electrode 127, andanother contact layer (not shown) may be provided between the upper cladlayer 125 and the second electrode 128. The contact layers may includeGaAs, GaP, AlGaAs, InGaP, or InGaAs. The contact layers may be dopedwith an impurity to facilitate current injection into the gain region123.

The first mirror region 122, the gain region 123, and the second mirrorregion 124 are arranged along in a horizontal direction, that is, in anX-axis direction as shown in FIG. 2. The first mirror region 122 and thesecond mirror region 124 reflect light generated in the gain region 123,and amplify light satisfying a particular (or, alternatively,predetermined) resonance condition and allow the amplified light to exitthe edge emitting device 120 as light 132.

The first mirror region 122 and the second mirror region 124 may have agrating pattern configured to reflect light. The grating pattern has ahorizontal repetition direction (the X-axis direction). Reflectivity maybe adjusted according to the shape or repetition period of the gratingpattern. In addition, the first mirror region 122 and the second mirrorregion 124 may be adjusted to have different reflectivities so as tocontrol the direction in which light exits. For example, the firstmirror region 122 may have a reflectivity of about 90% or greater, andthe second mirror region 124 may have lower reflectivity than the firstmirror region 122. In this case, light may exit to the side surface 120b through the second mirror region 124. However, this is a non-limitingexample. In addition to the grating pattern, the first and second mirrorregions 122 and 124 may employ (“include”) various structures configuredto perform a reflection function to form a resonator together with thegain region 123.

The edge emitting device 120 may further include: a semiconductoroptical amplifier configured to further amplify light amplified whileresonating in the laser cavity LC and exiting the edge emitting device120; and a waveguide structure to guide light to a desired position.

In the above description, the basic configuration of the edge emittingdevice 120 is described, but the edge emitting device 120 is not limitedthereto. The edge emitting device 120 may include a Fabry-Perot laserdiode or a distributed feedback (DFB) laser diode. In addition, anystructure having a lateral light exit surface may be employed.

The substrate 110 includes: a cathode 114 and an anode 112 respectivelyconnected to the two electrodes 127 and 128 of the edge emitting device120; and an insulating layer 116 electrically separating (“isolating,”“insulating,” etc.) the cathode 114 and the anode 112 from each other.The cathode 114 may be directly or indirectly in contact with the firstelectrode 127 provided on a lower surface of the edge emitting device120, and the anode 112 may be connected through a wire 130 to the secondelectrode 128 provided on an upper surface of the edge emitting device120.

The substrate 110 may also be configured to function as a heat sinkdischarging heat generated from the edge emitting device 120. That is,heat from the edge emitting device 120 may be discharged to the outsidethrough the cathode 114 including a metallic material.

The meta projector 100 may be provided as an integrated module. That is,the substrate 110, the meta-structure layer MS, and the path changingmember 140 may be provided as an integrated module. The meta projector100 may further include a housing 160 configured to fix the substrate110, the meta-structure layer MS, and the path changing member 140Restated, the housing 160 may fix the substrate 110, the meta-structurelayer MS, and the path changing member 140, such that the meta projector100 is an integrated module. An “integrated module” will be understoodto refer to a device that is an assembly of elements that arepermanently coupled (“fixed”) to each other, such that an interior ofthe assembly is sealed or substantially sealed (e.g., sealed withinmanufacturing tolerances and/or material tolerances) from externalmechanical manipulation and the assembly may be referred to as a single,individual element.

The meta-structure layer MS includes a plurality of nanostructures NShaving a sub-wavelength shape dimension that is smaller than thewavelength of light exiting the edge emitting device 120.

Referring to FIG. 3, a configuration of the meta-structure layer MS willbe described.

The plurality of nanostructures NS included in the meta-structure layerMS have at least one sub-wavelength shape dimension that is smaller thanthe wavelength λ of light 132 emitted from the edge emitting device 120.Here, the ‘shape dimension’ means a numerical value of a dimensionincluding a thickness or cross-sectional width defining the shape of thenanostructures NS.

The thicknesses (t) of the nanostructures NS are smaller than thewavelength λ of light 132 emitted from the edge emitting device 120. Inaddition, the arrangement pitch P of the nanostructures NS is smallerthan the wavelength λ.

In some example embodiments, the shape dimension and/or the arrangementpitch P of the nanostructures NS may be equal to or less than one-halfof the wavelength λ of light emitted from the edge emitting device 120.The nanostructures NS may be configured to operate as a strongscattering unit forming a meta-structure. As the arrangement pitch Pbecomes smaller than the wavelength λ, incident light 132 on thenanostructures NS may be controlled to have a desired shape without highorder diffraction, based on the at least one sub-wavelength shapedimension of the plurality of nanostructures NS.

Although the nanostructures NS are illustrated as having a cylindricalshape, the nanostructures NS are not limited thereto. Cross-sections ofthe nanostructures NS perpendicular to the thickness “t” direction ofthe nanostructures NS, that is, parallel with an XY plane, may havevarious shapes such as a polygonal shape, a cross shape, a star shape,or an asymmetric shape. In addition, although the nanostructures NS areillustrated as having the same shape (“a common shape”), thenanostructures NS are not limited thereto. For example, nanostructuresNS having various shapes may be provided on the meta-structure layer MS.

The meta-structure layer MS may further include a support layer SU thatsupports the plurality of nanostructures NS. The support layer SU mayinclude a dielectric material. For example, the support layer SU mayinclude a polymer material such as polycarbonate (PC), polystyrene (PS),or polymethylmethacrylate (PMMA), or SiO₂.

The nanostructures NS may include a dielectric material. Thenanostructures NS may include a material having a refractive indexgreater than the refractive index of a separate material that isadjacent to the plurality of nanostructures NS (e.g., a support layerSU). The nanostructures NS may include a material having a refractiveindex greater than the refractive index of the support layer SU. Forexample, the nanostructures NS may include any one of single crystalsilicon, polycrystalline silicon (poly Si), amorphous silicon, Si₃N₄,GaP, TiO₂, AlSb, AlAs, AlGaAs, AlGaInP, BP, and ZnGeP₂.

In some example embodiments, the plurality of nanostructures NS mayinclude a conductive material. The conductive material may be a highlyconductive metallic material configured to induce surface plasmonexcitation. For example, the plurality of nanostructures NS may includeat least any one selected from copper (Cu), aluminum (Al), nickel (Ni),iron (Fe), cobalt (Co), zinc (Zn), titanium (Ti), ruthenium (Ru),rhodium (Rh), palladium (Pd), platinum (Pt), silver (Ag), osmium (Os),iridium (Ir), gold (Au), and an alloy including any one of the listedelements. In addition, the nanostructures NS may include a highlyconductive two-dimensional material such as graphene, or a conductiveoxide.

In some example embodiments, some of the nanostructures NS may include adielectric material having a high refractive index, and some of thenanostructures NS may include a conductive material. That is, some ofthe nanostructures NS may include a dielectric material having(“associated with”) a refractive index greater than the refractive indexof the substrate 110, and the other of the nanostructures NS may includea conductive material.

Each of the above-described nanostructures NS may be associated with aunique transmission intensity and transmission phase depending on thematerial and shape thereof. The phase or intensity distribution of lightpassing through the meta-structure layer MS may be controlled byadjusting the shape distribution of the nanostructures NS. Hereinafter,the term ‘shape distribution’ refers to at least any one of the shape ofthe plurality of nanostructures NS, the size of the plurality ofnanostructures NS, the size distribution of the plurality ofnanostructures NS, the arrangement pitch of the plurality ofnanostructures NS, and the arrangement pitch distribution of theplurality of nanostructures NS. In some example embodiments, theplurality of nanostructures NS are associated with a particular shapedistribution that is a regular distribution or a random distribution,such that the plurality of nanostructures are configured to formstructured light SL having a particular pattern based on receiving thelight 132 emitted from the edge emitting device 120. The shapedistribution of the plurality of nanostructures NS may be associatedwith deflecting and outputting the structured light SL in a particulardirection. In some example embodiments, a shape distribution of theplurality of nanostructures is associated with different transmissionphase distributions based on polarization of incident light.

Although it is illustrated that all the nanostructures NS have the sameshape, size and height, this is an example. That is, the nanostructuresNS are not limited thereto. For example, the horizontal or vertical sizeor material of the nanostructures NS may be adjusted according to thepositions of the nanostructures NS so as to cause the plurality ofnanostructures NS to generate structured light SL having a particulartransmission intensity distribution or a particular transmission phasedistribution based on incident light 132 on the meta-structure layer MS,such that the plurality of nanostructures NS may be referred to as being“associated with” the particular transmission intensity distribution orthe particular transmission phase distribution. In order to cause theplurality of nanostructures NS to generate structured light SL having aparticular transmission intensity distribution or transmission phasedistribution, the shape distribution of a group of a plurality ofnanostructures NS may be determined according to the positions of thenanostructures NS. In addition, such groups of nanostructures NS may berepeatedly arranged at a particular (or, alternatively, predetermined)period. The shape distribution of the plurality of nanostructures NS maybe regular, periodic, or pseudo-periodic. However, the shapedistribution of the plurality of nanostructures NS is not limitedthereto. For example, the shape distribution of the plurality ofnanostructures NS may be random.

The meta-structure layer MS may have an ultra-small pitch and a thinthickness compared with micro-optical components of the related art, andthus may form an arbitrary pattern over a wide angular range withouthigh order diffraction. Therefore, the meta projector 100 may have anultra-small size (e.g., a relatively small size). For example, thethickness H of the meta projector 100 may be about 4 mm or less.

Restated, based on including a plurality of nanostructures NS asdescribed herein, wherein the plurality of nanostructures NS have one ormore physical distributions (e.g., shape distribution) as describedherein such that the plurality of nanostructures NS are configured togenerate structured light SL having a particular pattern based on light132 emitted from the edge emitting device 120 being incident on theplurality of nanostructures NS, a meta projector may be configured togenerate structured light SL having the particular pattern whileretaining a relatively small (“compact”) size. As a result, the metaprojector may provide improved capital costs of manufacture for the metaprojector and one or more devices that may incorporate the metaprojector. The meta projector, by virtue of reduced cost and/or size,may be more economically and/or practically incorporated into electronicdevices to enable the electronic devices to implement augmented reality(AR), virtual reality (VR), or mixed reality (MR). In addition, the metaprojector may be used as a light source to form structured light indepth sensors used for accurate three-dimensional shape recognition. Asa result, based on including the plurality of nanostructures NS asdescribed herein, a meta projector may address issues associated withpractical and/or economic incorporation of projectors associated withuser interfaces, augmented reality (AR), virtual reality (VR), or mixedreality (MR), some combination thereof, or the like into electronicdevices.

FIG. 4 is a perspective view illustrating an example configuration ofanother meta-structure layer MS1 applicable to the meta projector 100 ofFIG. 1.

A plurality of nanostructures NS provided on the meta-structure layerMS1 may have a random shape distribution in order to be configured toform a structured light SL having a particular pattern. FIG. 4illustrates that the widths w1, w2, w3 of the nanostructures NS aredifferent at different positions. However, this is a non-limitingexample. For example, the arrangement positions and shapes of thenanostructures NS may also be random instead of being regular overpositions.

FIGS. 5 to 8 are perspective views illustrating example shapes ofnanostructures NS that may be applied to (“included in”) themeta-structure layer MS of the meta projector 100 illustrated in FIG. 1.

Referring to FIG. 5, a nanostructure NS may have a tetragonal pillarshape with a thickness (t). The cross-sectional shape of the tetragonalpillar may be a square shape having a length D on a side, but is notlimited thereto. For example, the cross-sectional shape of thetetragonal pillar may be rectangular. The nanostructure NS may bemodified to have another polygonal pillar shape.

Referring to FIG. 6, the cross-sectional shape of a nanostructure NS maybe a cross shape. Although it is illustrated that the nanostructure NShas a symmetric shape, this is an example. That is, the nanostructure NSmay be modified to have an asymmetric shape. Restated, shapes ofcross-sections of the plurality of nanostructures NS parallel to theupper surface 120 a of the edge emitting device 120 may have asymmetry.

The nanostructure NS may have an asymmetric shape to form differenttransmission phase distributions depending on the polarization ofincident light.

Referring to FIG. 7, a nanostructure NS may have an asymmetricelliptical pillar shape. The nanostructure NS may have an ellipticalshape with a major-axis length D_(L) being different from a minor-axislength D_(S), and in this case, different transmission phasedistributions may appear in polarized light parallel to the major axisand polarized light parallel to the minor axis. That is, differentoptical operations may be respectively performed on light polarizedparallel to the major axis and light polarized parallel to the minoraxis.

Referring to FIG. 8, a nanostructure NS may have an asymmetricrectangular parallelepiped shape having a rectangular cross-section witha length D_(x) and a width D_(y). Like the shape shown in FIG. 7, thisshape may result in different transmission phase distributions dependingon the polarization of incident light. For example, different opticaleffects may be obtained depending on the polarization of incident light.

The nanostructures NS having the shapes illustrated in FIGS. 5 to 8,combinations of the nanostructures NS, or modifications thereof may beapplied to the meta-structure layer MS of the meta projector 100 shownin FIG. 1 in a regularly arranged form as shown in FIG. 3 or a randomlyarranged form as shown in FIG. 4. The nanostructures NS of theMeta-structure layer MS may be adjusted in shape, size, and arrangementso as to convert light exiting the edge emitting device 120 intostructured light having a pattern. In addition, the shape distributionof the nanostructures NS may be determined so as to adjust opticalperformance such as the beam diameter, converging/diverging, anddirection of exiting light.

If asymmetric nanostructures NS are employed, the above-describedoptical operations may be performed on light having specificpolarization directions distinguishable by asymmetry. For example, rulesfor arranging asymmetric nanostructures NS may be varied according tothe direction of polarization, so as to obtain different structuredlight forms from light having different polarizations.

FIG. 9 is a perspective view illustrating an example configuration ofanother meta-structure layer MS3 applicable to the meta projector 100shown in FIG. 1.

The meta-structure layer MS3 may include a plurality of nanostructuresNS on both sides of a support layer SU, where separate pluralities ofnanostructures NS1 and NS2 are on opposite, respective sides of thesupport layer SU. As shown in FIG. 9, a plurality of nanostructures NS1may be arranged on a lower surface SUa of the support layer SU to form aparticular (or, alternatively, predetermined) shape distribution, and aplurality of nanostructures NS2 may be arranged on an upper surface SUbof the support layer SU to form another particular (or, alternatively,predetermined) shape distribution.

The lower surface SUa of the supporting layer SU may face the edgeemitting device 120. That is, light 132 emitted from the edge emittingdevice 120 may first reach (“arrive at”) the lower surface SUa. In thiscase, the plurality of nanostructures NS1 arranged on the lower surfaceSUa of the support layer SU may have a particular shape distributionsuch that the plurality of nanostructures NS1 are configured to increasethe divergence angle of incident light. Restated, one plurality ofnanostructures NS1 on one side of the opposite sides of the supportlayer SU where the light 132 emitted from the edge emitting device 120first arrives may be associated with a shape distribution associatedwith a transmission phase distribution that increases a divergence angleof incident light 132. For example, the shape and transmission phasedistribution of the plurality of nanostructures NS1 may cause theplurality of nanostructures NS1 to be configured to perform a functionlike a concave lens. To this end, the shape distribution of theplurality of nanostructures NS1 may be such that the widths of theplurality of nanostructures NS1 may gradually increase from a referenceposition in a radial direction. This rule may be repeatedly applied toradial directions, and the period of repetition may not be constant. Inaddition, the shape and transmission phase distribution of thenanostructures NS1 may be associated with the nanostructures NS1 beingconfigured to perform a function like a concave lens having acylindrical surface or an ellipsoidal surface.

The plurality of nanostructures NS2 formed on the upper surface SUb ofthe support layer SU may have a shape distribution such that thenanostructures NS2 are configured to convert light 132 having adivergence angle widened by the plurality of nanostructures NS1 intostructured light SL having a particular (or, alternatively,predetermined) pattern.

The shapes of the nanostructures NS1 and NS2 may be selected from theshapes illustrated in FIGS. 5 to 8, combinations thereof, andmodifications thereof.

FIG. 10 is a cross-sectional view schematically illustrating aconfiguration of a meta projector 101 according to some exampleembodiments.

In some example embodiments, the meta projector 101 differs from themeta projector 100 illustrated in FIG. 1 in that the shape of a pathchanging member 141 of the meta projector 101 is different from theshape of the path changing member 140 of the meta projector 100. Thepath changing member 141 includes a reflective surface 141 a configuredto bend the propagation path of light 132 by a particular (or,alternatively, predetermined) angle, and the reflective surface 141 amay have a shape having a curved surface configured to adjust thedivergence angle of incident light. The reflective surface 141 a may bemirror-coated. The curved surface of the reflective surface 141 a may bespherical or aspherical, and may have a convex shape as shown in FIG. 10to increase the divergence angle of incident light.

The illustrated shape of the reflective surface 141 a is a non-limitingexample. For example, the reflective surface 141 a may have a concaveshape decreasing the divergence angle of incident light, or may have acurved shape varying the diverging direction of incident light accordingto positions.

FIG. 11 is a cross-sectional view schematically illustrating aconfiguration of a meta projector 102 according to some exampleembodiments, and FIG. 12 is a cross-sectional view illustrating anexample configuration of a meta-surface 142 a of the meta projector 102illustrated in FIG. 11.

In some example embodiments, the meta projector 102 of the is differentfrom the meta projector 100 illustrated in FIG. 1 in that themeta-surface 142 a is a reflective surface of a path changing member142.

Like a meta-structure layer MS, the meta-surface 142 a includes aplurality of nanostructures NS having (“associated with”) asub-wavelength shape dimension smaller than the wavelength of lightemitted from an edge emitting device 120. That is, the shapes and shapedistributions of the nanostructures NS described with reference to FIGS.3 to 9 may be applied to the meta-surface 142 a.

The shape distribution of the plurality of nanostructures NS of themeta-surface 142 a may be associated with the plurality ofnanostructures NS being configured to control the divergence angle ofincident light 132. For example, as shown in FIG. 12, the shapedistribution of the plurality of nanostructures NS may be associatedwith the plurality of nanostructures NS being configured to perform afunction like a convex mirror. The shape distribution of the pluralityof nanostructures NS may be so associated such that the widths of thenanostructures NS may gradually decrease in a radial direction from areference position. This rule may be repeatedly applied to radialdirections, and the period of repetition may not be constant. Inaddition, the shape and transmission phase distribution of thenanostructures NS may be associated with the plurality of nanostructuresbeing configured to perform a function like a convex mirror lens havinga cylindrical surface or an ellipsoidal surface.

In some example embodiments, a meta projector may include themeta-surface 142 a illustrated in FIG. 11 and may include, in place of ameta-structure layer MS including a plurality of nanostructures NS, alayer configured to refract a structured light SL generated by themeta-surface 142 a. The plurality of nanostructures NS included in themeta-surface 142 a may have any of the features (e.g., shapedistribution) of the plurality of nanostructures NS included in ameta-structure layer MS as described in any of the example embodimentsincluded herein. In some example embodiments, such a layer may befurther omitted from the meta projector, such that the meta-surface 142a generates a structured light SL pattern based on light 132 beingincident thereon, wherein the meta projector is configured to emit thestructured light SL generated by the meta-surface 142 a. A shapedistribution of the plurality of nanostructures of the meta-surface 142a is associated with forming structured light SL providing a keyboardimage in which a set of character keys is arranged or an image includingat least one icon.

In view of at least the above, it will be understood that, in someexample embodiments, a meta projector that includes the substrate 110and the edge emitting device 120 further includes a plurality ofnanostructures NS configured to receive the light 132 emitted from theedge emitting device 120 and generate a structured light SL patternbased on receiving the light 132 emitted from the edge emitting device,where the plurality of nanostructures NS have a sub-wavelength shapedimension, the sub-wavelength shape dimension smaller than a wavelengthof the light emitted from the edge emitting device, and wherein theplurality of nanostructures NS may be included in at least one elementof a meta-structure layer MS as described herein and a meta-surface 142a as described herein.

FIG. 13 is a cross-sectional view schematically illustrating aconfiguration of a meta projector 103 according to some exampleembodiments.

In the meta projector 103 according to some example embodiments, detailsof a meta-structure layer MS4 are determined (e.g., a plurality ofnanostructures NS in the meta-structure layer MS4 have a particularshape distribution) such that structured light SL formed by themeta-structure layer MS4 may reproduce a particular (or, alternatively,predetermined) arbitrary shape. For example, as shown in FIG. 13, astructured light image I_SL formed by the meta-structure layer MS4 maybe a keyboard image in which a set of character keys is arranged. Thestructured light image I_SL formed by the meta-structure layer MS4 maybe an image including at least one icon. The meta-structure layer MS4may include a plurality of nanostructures NS having a shape distributionconfigured to realize such a structured light pattern based on light 132being incident on the meta-structure layer MS4.

The illustrated structured light image I_SL is an example. For example,the structured light image I_SL may be an image in which one or moreicons or pointers are arranged. That is, the shape distribution of theplurality of nanostructures NS of the meta-structure layer MS4 may besuch that various images configured to provide an input means as a userinterface for a user may be reproduced by the meta projector 103 asstructured light images I_SL based on light 132 being incident onmeta-structure layer MS4.

Since the above-described meta projectors include meta-structure layersusing the shape distribution of nanostructures having a sub-wavelengthshape dimension, the above-described meta projectors may haveultra-small sizes. Therefore, the meta projectors may be applied tovarious electronic apparatuses such as mobile devices or wearabledevices. For example, the above-described meta projectors may be used asultra-small projectors for implementing augmented reality (AR), virtualreality (VR), or mixed reality (MR). In addition, the meta projectorsmay be used as light sources to form structured light in depth sensorsused for accurate three-dimensional shape recognition.

FIG. 14 is a block diagram schematically illustrating a user interfacedevice 1200 and an electronic apparatus 1000 including the userinterface device 1200 according to some example embodiments.

The electronic apparatus 1000 includes the user interface device 1200, aprocessor 1300, and a memory 1400.

The user interface device 1200 includes a meta projector 1210 configuredto reproduce a particular (or, alternatively, predetermined) structuredlight image I_SL and an imaging device 1230 configured to photograph thestructured light image I_SL formed by the meta projector 1210.

The structured light image I_SL reproduced by the meta projector 1210may be a keyboard image in which a set of character keys is arranged asshown in FIG. 14, but is not limited to. For example, the structuredlight image I_SL may be an image in which one or more icons or pointersare arranged.

A user may express input information using the character keys shown inthe structured light image I_SL. That is, a user may perform a desiredinput operation by touching character keys shown on the keyboard of thestructured light image I_SL with his/her fingers.

The imaging device 1230 is placed to photograph the structured lightimage I_SL. Images taken by the imaging device 1230 may be transmittedto the processor 1300 to extract a user input signal.

The processor 1300 is responsible for all processing and controllingoperations of the electronic apparatus 1000. In addition, the processor1300 may extract a user input signal from images captured by the imagingdevice 1230 and may execute one of execution modules (“programs ofinstruction”) stored in a memory 1400 according to the extracted userinput signal.

The memory 1400 may store one or more execution modules 1410 and 1420that may be executed by the processor 1300, and data necessary forexecuting the execution modules 1410 and 1420.

In addition, the memory 1400 may store modules for various applicationsto be executed by the electronic apparatus 1000, and according todevices included in the electronic apparatus 1000, the memory 1400 mayfurther include modules such as a communication module, a camera module,a video replay module, or an audio replay module.

The memory 1400 may include at least one type of recording mediumselected from a flash memory, a hard disk, a micro multimedia card, amemory card (e.g., a secure digital (SD) card or an extreme digital (XD)card, a random access memory (RAM), a static random access memory(SRAM), a read-only memory (ROM), an electrically erasable programmableread-only memory (EEPROM), a programmable read-only memory (PROM), amagnetic memory, a magnetic disk, or an optical disk.

For example, the electronic apparatus 1000 may be a portable mobilecommunication device, a smart phone, a smart watch, a personal digitalassistant (PDA), a laptop, a personal computer (PC), a mobile computingdevice, or a non-mobile computing device. However, the electronicapparatus 1000 is not limited thereto.

Since the user interface device 1200 including the meta projector 1210is configured to provide a structured light image I_SL as an inputinterface, the electronic apparatus 1000 may not include, for example, areal keyboard. Alternatively, the electronic apparatus 1000 may includea real keyboard, and a user may select whether to use the real keyboardor a keyboard provided by a structured light image I_SL.

FIG. 15 is a block diagram schematically illustrating a configuration ofa depth recognition apparatus 2000 according to some exampleembodiments.

The depth recognition apparatus 2000 includes a meta projector 2200configured to emit structured light SL_(i) toward an object OBJ, asensor 2400 configured to receiving structured light SL_(r) reflectedfrom the object OBJ, and a calculator 2600 configured to calculate adepth position of the object OBJ by comparing a pattern change betweenthe structured light SL_(i) emitted from the meta projector 2200 and thestructured light SL_(r) received by the sensor 2400.

The meta projector 2200 may convert light (e.g., light 132) emitted froman edge emitting device into structured light (e.g., structured lightSL) having a particular (or, alternatively, predetermined) pattern andmay output the structured light. The meta projector 2200 may include anyone of the meta projectors 100, 101, and 102 of the above-describedembodiments or a combination thereof.

The sensor 2400 senses the structured light SL_(r) reflected from theobject OBJ. The sensor 2400 may include an array of light detectingelements. The sensor 2400 may further include a spectroscopic element toanalyze light reflected from the object OBJ according to wavelengths.

The calculator 2600 may compare the structured light SL_(i) emittedtoward the object OBJ with the structured light SL_(r) reflected fromthe object OBJ so as to obtain depth information on the object OBJ andmay analyze the three-dimensional shape, position, motion, or the like,of the object OBJ based on the depth information. The structured lightSL_(i) generated by the meta projector 2200 is a pattern mathematicallycoded so as to uniquely designate angular position coordinates usingbright and dark points. When such a pattern strikes the object OBJhaving a three-dimensional shape and is then reflected from the objectOBJ, the pattern of reflected structured light SL_(r) is different fromthe pattern of incident structured light SL_(i). Depth information onthe object OBJ may be extracted by comparing such patterns and tracingpatterns according to coordinates, and in this manner, three-dimensionalinformation on the shape and motion of the object OBJ may be extracted.

Additional optical elements may be arranged between the meta projector2200 and the object OBJ so as to adjust the direction of structuredlight SL_(i) emitted from the meta projector 2200 toward the object OBJor additionally modulate the structured light SL_(i).

In addition, the depth recognition apparatus 2000 may further include: acontroller configured to generally control the operation of a lightsource of the meta projector 2200 or the operation of the sensor 2400;and a memory storing a calculation program to be used when thecalculator 2600 performs three-dimensional information extraction.

Results of calculation of the calculator 2600, that is, informationabout the shape and position of the object OBJ may be transmitted toanother unit. For example, such information may be transmitted to acontroller of an electronic apparatus including the depth recognitionapparatus 2000. A unit to which results of calculation are transmittedmay be a display device or a printer configured to output the results.In some example embodiments, the unit may be a smartphone, a cellularphone, a personal digital assistant (PDA), a laptop, a personal computer(PC), a wearable device, a mobile device, or a non-mobile computingdevice. However, the other unit is not limited to the listed devices.

The depth recognition apparatus 2000 may be used as a sensor configuredto precisely acquiring three-dimensional information on a front objectand thus may be applied to various electronic apparatuses. Examples ofsuch various electronic apparatuses may include: an autonomous driveapparatus such as an unmanned vehicle, an autonomous drive vehicle, anautonomous drive robot, or an autonomous drive drone; a mobilecommunication apparatus; and an Internet of Things (IoT) apparatus.

In the above-described meta projectors, light emitted from an edgeemitting device may be converted into structured light having variouspatterns by a meta-structure layer having sub-wavelength nanostructures.

The above-described meta projectors may be easily implemented asintegrated modules having ultra-small sizes.

The above-described meta projectors may be applied to various electronicapparatuses. For example, the above-described meta projectors may beapplied to depth recognition apparatuses for precise motion sensing andthree-dimensional shape sensing.

The operations described in the embodiments are examples which are notintended to limit the scope of the inventive concepts. In the presentdisclosure, descriptions of known electric components, control systems,software, and other functional aspects thereof may not be given forconciseness. Furthermore, in the drawings, connection lines or membersbetween elements are functional, physical, and/or electric connectionsillustrated as examples that can be replaced with or used together withother functional, physical, and/or electrical connections.

Example embodiments have been described and illustrated with referenceto the accompanying drawings to help understanding of the inventiveconcepts. However, these embodiments are merely example not limiting thescope of the inventive concepts. In addition, it will be understood thatthe inventive concepts is not limited to those illustrated and describedin the present disclosure. That is, those of ordinary skill in the artmay make various modifications therefrom.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within some exampleembodiments should typically be considered as available for othersimilar features or aspects in other example embodiments.

While one or more example embodiments have been described with referenceto the figures, it will be understood by those of ordinary skill in theart that various changes in form and details may be made therein withoutdeparting from the spirit and scope as defined by the following claims.

What is claimed is:
 1. A meta projector comprising: a substrate; an edgeemitting device on the substrate, the edge emitting device including anupper surface extending parallel to the substrate and a side surfaceinclined relative to the upper surface, the edge emitting deviceconfigured to emit light through the side surface; a meta-structurelayer spaced apart from the upper surface of the edge emitting device,the meta-structure layer including a plurality of nanostructures havinga sub-wavelength shape dimension, the sub-wavelength shape dimensionsmaller than a wavelength of the light emitted from the edge emittingdevice; and a path changing member configured to change a path of thelight emitted from the edge emitting device to direct the path towardthe meta-structure layer, wherein the meta-structure layer furtherincludes a support layer supporting the plurality of nanostructures, thesupport layer including a first surface facing the edge emitting deviceand a second surface opposite to the first surface wherein the pluralityof nanostructures includes plurality of first nanostructures on thefirst surface of the support layer and plurality of secondnanostructures on the second surface of the support layer, and wherein ashape distribution of first plurality of nanostructure and a shapedistribution of the plurality of second nanostructures are different toeach other.
 2. The meta projector of claim 1, wherein the plurality ofnanostructures are configured to adjust direction of the light emittedfrom the edge emitting device.
 3. The meta projector of claim 1, whereinthe plurality of nanostructures are configured to adjust beam diameterof the light emitted from the edge emitting device.
 4. The metaprojector of claim 1, wherein the plurality of first nanostructures areconfigured to increase a divergence angle of an incident light.
 5. Themeta projector of claim 1, wherein the plurality of first nanostructuresare configured such that widths of the plurality of first nanostructuresgradually increase from a reference position in a radial direction. 6.The meta projector of claim 1, wherein the plurality of firstnanostructures are configured such that the plurality of firstnanostructures function as a cylindrical surface or an ellipsoidalsurface.
 7. The meta projector of claim 1, further comprising: a housingfixing the substrate, the meta-structure layer, and the path changingmember, such that the meta projector is an integrated module.
 8. Themeta projector of claim 1, wherein the substrate includes a cathode andan anode respectively connected to two electrodes of the edge emittingdevice; and an insulating layer electrically isolating the cathode andthe anode from each other.
 9. The meta projector of claim 1, wherein theplurality of nanostructures include a material having a refractive indexhigher than a refractive index of the support layer.
 10. The metaprojector of claim 1, wherein the shape distribution of the plurality offirst nanostructures or the plurality of second nanostructures isassociated with different transmission phase distributions based onpolarization of incident light.
 11. The meta projector of claim 1,wherein shapes of cross-sections of the plurality of firstnanostructures or the plurality of second nanostructures parallel to theupper surface of the edge emitting device have asymmetry.
 12. The metaprojector of claim 1, wherein the plurality of first nanostructures orthe plurality of second nanostructures are associated with anarrangement pitch which is equal to or less than one-half of thewavelength of the light emitted from the edge emitting device.
 13. Themeta projector of claim 1, wherein the path changing member includes areflective surface including a meta-surface, the meta-surface includinga plurality of third nanostructures.
 14. The meta projector of claim 13,wherein a shape distribution of the plurality of third nanostructures isconfigured to adjust a divergence angle of incident light.
 15. A metaprojector comprising: a substrate; an edge emitting device on thesubstrate, the edge emitting device including an upper surface extendingparallel to the substrate and a side surface inclined relative to theupper surface, the edge emitting device configured to emit light throughthe side surface; a meta-structure layer spaced apart from the uppersurface of the edge emitting device, the meta-structure layer includinga plurality of nanostructures having a sub-wavelength shape dimension,the sub-wavelength shape dimension smaller than a wavelength of thelight emitted from the edge emitting device; and a path changing memberconfigured to change a path of the light emitted from the edge emittingdevice to direct the path toward the meta-structure layer, wherein ashape distribution of the plurality of nanostructures of themeta-structure layer is set for a transmission phase distribution tooutput structured light providing a keyboard image in which a set ofcharacter keys is arranged or an image including at least one icon. 16.An electronic device comprising the meta projector of claim
 1. 17. Theelectronic device of claim 16, wherein the electronic device is a mobiledevice.
 18. The electronic device of claim 16, wherein the electronicdevice is a wearable device.